The extension of continuous carbon emission monitoring system in China’s thermal power plants under the carbon market

Six mercury continuous emission monitoring (CEM) systems provided by two leading mercury (Hg) CEM system manufacturers were tested at five coal combustion utilities. The linearity, response time, day-to-day stability, efficiency of the Hg speciation modules, and ease of use were evaluated by following procedures specified in the Code of Federal Regulation Title 40 Part 75 (40 CFR Part 75). Mercury monitoring results from Hg CEM systems were compared to an EPA-recognized reference method. A sorbent trap sampling system was also evaluated in this study to compare the relative accuracy to the reference method as well as to Hg CEM systems. A conceptual protocol proposed by U.S. EPA (Method 30A) for using an Hg CEM system as the reference method for the Hg relative accuracy (RA) test was also followed to evaluate the workability of the protocol. This paper discusses the operational experience obtained from these field studies and the remaining challenges to overcome while using Hg CEM systems and the sorbent trap method for continuous Hg emission monitoring. 3 refs., 5 figs., 11 tabs.

Some manufacturing, research, and development conducted within AT&T involves processes that emit air contaminants. These emissions are confined, scrubbed to recover the constituents, and vented outside through stacks. Continuous emission monitoring (CEM) systems analyze the emissions in near-real time and provide feedback to control them. The information collected from CEM systems in some industries is used to prove compliance with applicable environmental regulations. This paper describes CEM technology and an Environmental Monitoring and Reporting System (EMARS) for near-real-time emissions monitoring. It also presents selected applications in AT&T Bell Laboratories and AT&T manufacturing facilities at Montgomery and Richmond.

Per State of Qatar environmental regulations, Continuous Emission Monitoring Systems (CEMS) are required to be installed on combustion units with a heat input capacity of greater than 25 megawatts (MW). CEMS are well regulated in US and European jurisdictions to monitor air emissions compliance. However, CEMS entail extensive calibration requirements and are difficult to maintain and operate in the harsh climate of the Arabian Gulf. Based on the challenges noted above, Qatargas Operating Company Limited (Qatargas) and TOTAL E&P Qatar (TOTAL) collaborated on a study to assess the viability of Predictive Emissions Monitoring Systems (PEMS) as a reliable and sustainable emissions monitoring technique. The first part of the study focused on the development of PEMS algorithms and comprised a blind benchmarking evaluation of the three main types of PEMS technologies (first principles, statistical and neural networks) using data collected from an operating Qatargas gas turbine. The second part of the study assessed the operational, maintenance and cost aspects of PEMS installation with reference to international guidelines. This paper summarizes results of the first part of the above study which includes the results of the technical, blind benchmarking comparison of PEMS technologies on the pilot gas turbines. These results suggest that PEMS measurements can be as accurate as that of CEMS. One of the advantages of PEMS, being a software based-solution, is the reduced requirement for installation of additional physical monitoring instrumentation, which translates into substantially lower capital and operational costs as well as reduced calibration and maintenance requirements. The findings of the second part of the study with regard to installation and operation of PEMS installations will be discussed in a future paper. PEMS have been successfully regulated in several worldwide jurisdictions, including by the USEPA. This paper aims to demonstrate that PEMS can be a viable emission monitoring tool as both an alternative and complementary capacity to CEMS. Introduction Many current regulations require traditional direct emission monitoring of fired units using Continuous Emission Monitoring Systems (CEMS). This is normally intended to monitor compliance against operating permits and/or regulatory limits. CEMS is an extractive sampling device installed on the exhaust stack of a fired unit to extract flue gas samples for emissions measurement. This direct monitoring system requires frequent maintenance and calibration. Over a period of direct exposure to the flue gas, the CEMS analyzers drift and require periodic adjustments in the form of calibrations using reference calibration gas standards. On the other hand, software-based monitoring systems such as Predictive Emission Monitoring Systems (PEMS) predict or estimate emissions from fired units using the units' operating parameters as a basis. This predictive approach therefore does not require physical emissions measurement and hence significantly minimizes associated maintenance and calibration requirements.

According to the Russian environmental legislation, all sources of atmospheric pollution at Category I industrial enterprises must necessarily be equipped with automatic systems for monitoring and accounting of marker pollutants emissions. Such industrial facilities include more than 100 thermal power plants. The list of marker pollutants has been established in the relevant industry information and technical reference books on the best available technologies (ITR BAT). The list of marker pollutants monitored at thermal power plants by automatic systems includes nitrogen oxides NOX, sulfur dioxide SO2, carbon monoxide CO, and solid fuel ash. The use of domestically produced measuring equipment for these purposes is set forth as a priority task. However, there is currently no systematic information about gas analysis systems available in the market. The measuring instruments are analyzed, and a database of domestic sampling and non-sampling gas analytical systems is set up, which includes the main methods and means of measuring pollutants emissions, the technical characteristics of which meet the requirements of regulatory documents, and which allows specialists to optimally choose measuring instruments for organizing a continuous emission monitoring system (CEMS) at thermal power plants, taking into account specific conditions and requirements. The Microsoft Access Relational Database Management System (DBMS), which is a flexible database management system, is used to create the database. The developed database of measuring instruments for emission monitoring includes equipment from 33 Russian companies. The DBMS enables the user to organize data in tabular form and produce requests for selecting certain specified parameters. Both basic and additional criteria for selecting measuring instruments can be included in the request form. The developed DBMS takes into account the measured parameters of medium, the measurement method and means, compliance with BAT, measurement ranges and errors, estimated and warranty service life, mass and dimensional characteristics, and cost and complexity of maintenance, all serving for the convenience of selecting and implementing CEMS at thermal power plants. An example of the choice of measuring instruments from the proposed database for monitoring the marker pollutants emissions for the MPEI thermal power plant using the optimal choice algorithm is given.

Continuous emission monitoring system (CEMS) has been widely used in many engineering fields. Common cause failures (CCFs) have remarkable effects on the system reliability of CEMS, because of shared work conditions and dependent failures for different components. A method for reliability evaluation of CEMS with CCFs is proposed based on fuzzy Failure Mode Effects and Criticality Analysis (FMECA) as well as Bayesian network (BN). By introducing the system composition and function principles of CEMS, the CEMS failure mode is clearly defined and the weak components of the system are identified. According to the hazard ranking of the CEMS failure modes, the places where reliability improvement or preventive maintenance should be implemented are found out. Then, BN-based reliability model of the sampling system, which is the weakest subsystem of CEMS, is constructed according to the results of a fault tree analysis. The behavior of CCF is further incorporated, and the α-factor model is used to evaluate the probability of CCF. Lastly, a numerical example is used to illustrate the proposed method. A comparison between the proposed method and the one without considering CCF is carried out. The result demonstrates that the proposed method has better reliability assessment accuracy for the CEMS with CCF than the one without considering CCF.

Continuous emission monitoring systems at power plants in China: Improving SO 2 emission measurement

Continuous Emissions Monitoring Systems (CEMS) permanently installed for selected processes require initial and periodic quality assurance audit tests to ensure that they are functioning properly and reporting emissions accurately. Depending on the industry and process type, there are several sets of regulations that dictate the exact QA/QC requirements that the CEMS must meet. Measurement data by CEMS is a legal base to charge for pollutant emission. But the great masses of CEMS have some problems of high data drift and low measurement accuracy etc. For evaluating CEMS Relative Accuracy, we simultaneously compared SO_2/NOx and Dust monitoring systems with CEMS and normal handmade sampling method at different boiler load. It draws a conclusion that Relative Accuracy Test Audit (RATA) of SO_2/NOx monitoring systems goes beyond criterion. The data should be corrected. Continuous Opacity monitoring systems is exact. CEMS should carry out RATA and Bias Test to ensure measurement data validation and accuracy.

According to Federal Law no. 219-FZ, dated July 21, 2014, all enterprises that have a significant negative impact on the environment shall continuously monitor and account emissions of harmful substances into the atmospheric air. The choice of measuring equipment that is included in continuous emission monitoring and accounting systems (CEMA in particular, its solution requires a comparative analysis of gas analysis systems; each of these systems has its advantages and disadvantages. In addition, the choice of gas analysis systems for CEM&ASs should be maximally objective and not depend on preferences of separate experts and specialists. The technique of choosing gas analysis equipment that was developed in previous years at Moscow Power Engineering Institute (MPEI) has been analyzed and the applicability of the mathematical tool of a multiple criteria analysis to choose measuring equipment for the continuous emission monitoring and accounting system have been estimated. New approaches to the optimal choice of gas analysis equipment for systems of the continuous monitoring and accounting of harmful emissions from thermal power plants have been proposed, new criteria of evaluation of gas analysis systems have been introduced, and weight coefficients have been determined for these criteria. The results of this study served as a basis for the Preliminary National Standard of the Russian Federation “Best Available Technologies. Automated Systems of Continuous Monitoring and Accounting of Emissions of Harmful (Polluting) Substances from Thermal Power Plants into the Atmospheric Air. Basic Requirements,” which was developed by the Moscow Power Engineering Institute, National Research University, in cooperation with the Council of Power Producers and Strategic Electric Power Investors Association and the All-Russia Research Institute for Materials and Technology Standardization.

Predictive NO x emission monitoring on board a passenger ferry

A field test program was conducted to evaluate the long-term performance of several gas continuous emission monitoring systems (CEMS).* This paper presents the results gathered on the long-term accuracy and calibration drift characteristics of ten CEMS installed at scrubber-controlled, coal-fired power plants. The program involved periodic accuracy audits and a review of available calibration drift data for selected CEMS. Accuracy audit results show that both SO2 and NOx CEMS are capable of providing accurate data on a long-term basis. However, frequent audits are necessary in order to verify the performance of an individual CEMS. The results of the calibration drift data evaluation show that despite infrequent occurrences of excessive drift, CEMS operated with a significant bias for extended time periods simply because corrective action was not taken in a timely manner.

Carbon and air pollutant emission dynamics of small-scale industrial sectors based on CEMS: a case of tobacco curing industry.

Since passage of the 1990 Clean Air Act Amendments (CAAA), continuous emission monitoring system (CEMS) vendors, manufacturers, research organizations, parametric emissions monitoring system (PEMS) vendors, consultants, and source owner/operators have been developing strategies to satisfy compliance monitoring requirements that may eventually apply to many gas turbines and engines. A variety of CEMS and PEMS approaches have been developed, and evaluated to determine overall performance and cost. In addition, a few natural gas transmission companies have been required to install and operate CEMS on specific engines and turbines in order to comply with existing State permitting requirements or emissions trading programs.Within the next five years, the Environmental Protection Agency (EPA) is expected to promulgate a series of stationary source, air emission regulations that will have a significant impact on many industrial sources. In addition, EPA will be issuing regulatory revisions, policy manuals and guidance documents to further clarify the implementation and enforcement of rules recently promulgated - e.g., Title V Permitting, Compliance Assurance Monitoring (CAM) and Credible Evidence rules. As a part of each of these anticipated rules, revisions, and supporting documents, EPA will require and continue to refine corresponding compliance monitoring procedures and performance specifications. For the natural gas transmission industry, the anticipated regulatory changes could result in substantial increases in the cost of environmental compliance. Costs associated with pollution control (including reductions in engine/turbine efficiency), compliance monitoring, emissions reporting and recordkeeping may all increase as a result of pending regulatory requirements. This report has been prepared to document the natural gas transmission industry's experience operating continuous emission monitoring systems (CEMS) on reciprocating engines and stationary gas turbines and to discuss some of the more critical, technical issues that will have to be addressed if pending regulatory changes require the use of CEMS. In particular, this report provides technical discussions regarding the performance, operation, maintenance and costs of a CEMS program for compliance monitoring of nitrogen oxides emissions.

Per State of Qatar environmental regulations, Continuous Emission Monitoring Systems (CEMS) are required to be installed on combustion units with a heat input capacity of greater than 25 megawatts (MW). CEMS are well regulated in US and European jurisdictions to monitor air emissions compliance. However, CEMS entail extensive calibration requirements and are difficult to maintain and operate in the harsh climate of the Arabian Gulf. Based on the challenges noted above, Qatargas Operating Company Limited (Qatargas) and TOTAL E&P Qatar (TOTAL) collaborated on a study to assess the viability of Predictive Emissions Monitoring Systems (PEMS) as a reliable and sustainable emissions monitoring technique. The first part of the study focused on the development of PEMS algorithms and comprised a blind benchmarking evaluation of the three main types of PEMS technologies (first principles, statistical and neural networks) using data collected from an operating Qatargas gas turbine. The second part of the study assessed the operational, maintenance and cost aspects of PEMS installation with reference to international guidelines. This paper summarizes results of the first part of the above study which includes the results of the technical, blind benchmarking comparison of PEMS technologies on the pilot gas turbines. These results suggest that PEMS measurements can be as accurate as that of CEMS. One of the advantages of PEMS, being a software based-solution, is the reduced requirement for installation of additional physical monitoring instrumentation, which translates into substantially lower capital and operational costs as well as reduced calibration and maintenance requirements. The findings of the second part of the study with regard to installation and operation of PEMS installations will be discussed in a future paper. PEMS have been successfully regulated in several worldwide jurisdictions, including by the USEPA. This paper aims to demonstrate that PEMS can be a viable emission monitoring tool as both an alternative and complementary capacity to CEMS.

An improved hourly-resolved NOx emission inventory for power plants based on continuous emission monitoring system (CEMS) database: A case in Jiangsu, China

Continuous Emission Monitoring Systems (CEMS) generally refers to a packaged system of gas analyzers, gas sampling system, temperature, flow and opacity monitors that are integrated with a data acquisition system to demonstrate environmental regulatory compliance of various industrial sources of air pollutants. CEMS are useful tools in gathering process emissions data for environmental compliance demonstration and process control and optimization. Accurate, reliable emission monitoring can be tricky. Probes must be designed and built to provide reliable service without plugging or corrosion. The sample transport system must deliver a representative sample to the analyzers without sample loss or degradation, and the analytical system must provide reliable and unbiased results taking into account any interferents present in the gas stream. This paper will mainly design a set of CEM system for flue gas from thermal power plant.