MMBtu Research Articles

Feasibility Study of Biogas Upgrading Facility Development from Anaerobic Digestion of Palm Oil Mill Effluent in Indonesia

Palm Oil Mill Effluent (POME) can be processed using anaerobic digestion technologies to produce biogas. Biogas, that was produced from the anaerobic digestion process from POME, contained a high impurity CO2 30% - 45% and H2S around 1500 - 3000 ppm. In this research, a feasibility study was conducted to develop an anaerobic digestion facility from POME and biogas upgrading facility using absorption-based technologies: water scrubbing and amine scrubbing. The technical study was carried out using Aspen Plus software with a biogas flow rate of 0.8 MMCFD and methane content in biogas of 65% mole fraction. The target biomethane product contains CH4> 95%, CO2< 5%, H2S < 10 ppm and water content<10 lb/MMscf. The investment and operating costs for an aerobic digestion facilities use data from previous biogas projects that have been registered in the UNFCCC CDM (Clean Development Mechanism) project in Indonesia. Meanwhile, the biogas upgrading facility's investment cost is obtained from the simulation results using Aspen Plus software. An economic study was conducted to calculate the gas price of biomethane with an expected internal rate of return of 12%. The purity level of biomethane from water scrubbing facilities reached 97.38% and from amine scrubbing facilities reached 99.93%. From the simulation and calculation result, the lowest gas price of biomethane was $ 13.06/MMB tu using amine scrubbing technology.

A STUDY ON THE SHARES OF SEVERAL INDEPENDENT VARIABLES IN PREDICTING THE DOMESTIC GAS PRICE

End users of natural gas have long waited for the government regulation on a more rational gas price. In 2017, the answer to the end users is the new Energy and Mineral Resources Ministerial Decree number 434 K/12/MEM/2017 on the supervision of energy business activities, one of which is the natural gas sector. Prior to the stipulation, the price of natural could reach over $ 12 / MM BTU. Thus, the decree stipulates the price of natural gas should be $ 9,95 / MMBTU. This paper aims at capturing the closer profiles of variables that might have profound impact on the price of domestic natural gas. Analytical Data Tools used in this study are the IBM – SPSS and XLSTAT In the end, the study resulting the price range suggestion, that is in still in line with the government suggested price

Livestock manure and crop residue for energy generation: Macro-assessment at a national scale

Abstract Livestock manure and crop residue can be processed in an environmentally acceptable way through anaerobic digestion to generate biogas, also, under an integrated production scheme, providing fertiliser and heat as by-products. The most valuable use of the produced biogas (i.e. for the generation of electricity or a gaseous biofuel) depends on specific economic conditions and other constraints which cannot be generalised. From a GIS-based biomass resource inventory, manure and agriculture residue were evaluated as substrates for the generation of electricity or biomethane for injection into the natural grid, and then comparatively assessed at national level in Chile. Mathematical modelling was used to calculate supply–cost curves for the purpose of estimating the representative generation cost of both secondary energy end-products as well as their technical and economic potential. The mono-digestion of manure and mono-digestion of agricultural residue as well as the co-digestion of both substrates were assessed. From manure processing, the estimated economic potential was 0.8 TWhe y−1 of electricity at a representative generation cost of 25 ct€ kWhe−1, while that of biomethane was calculated to be 182 MM Nm3 y−1 at a representative generation cost of 98 € MM BTU−1. In addition, the economic potential for the mono-digestion of agricultural residue was estimated to be 1.1 TWhey−1 at a representative generation cost of 15.4 ct€ kWhe−1, while that of biomethane generation was 280 MM Nm3 y−1 at a generation cost of 40 € MM BTU−1. Manure co-digestion offered a significant increase of roughly 46% of the economic potential at the same representative cost as mono-digestion. The co-digestion option of using biomethane production for injection does not seem to be adequate when considering a national policy to boost biogas production. Electricity generation, however, may be a viable option that has major economic advantages with or without a feed-in tariff scheme.

Thermoeconomic Analysis of High-Temperature Gas-Cooled Reactors with Steam Methane Reforming for Hydrogen Production

Thermoeconomic analysis was performed for high-temperature gas-cooled reactors (HTGRs) coupled with a steam methane reforming (SMR) plant in order to estimate the hydrogen production cost. Two possible HTGRs, a modified Brayton cycle HTGR (GT-HTGR) coupled with an SMR plant and a modified steam cycle HTGR (SC-HTGR) coupled with an SMR plant, were considered in this study. In these analyses, mass and energy conservation were applied strictly to each component of the system. Also, quantitative balances of the exergy and the exergetic cost for each component and for the whole system were carefully considered. The hydrogen production cost was estimated to be about $0.825/kg [$7.25/one million Btu (MM Btu)] for the GT-HTGR-SMR system and $0.728/kg ($6.41/MM Btu) for the ST-HTGR-SRM system with a uranium fuel cost of $8.40/MW·h. The hydrogen production cost estimated in this study is considerably less than the economic target of $1.70/kg ($14.96/MM Btu), indicating that hydrogen production using HTGR with an SMR plant has great economic potential.

Forecasting the optimal cost of energy conservation by sectors to the year 2000

This paper suggests that government policies to induce or mandate energy conservation across sectors should be based on cost-effective measures. Section 2 outlines the concept of cost-effectiveness by sector according to the marginal cost MC of conservation and the aggregation of the MC curves in a horizontally added aggregate marginal cost curve AMC or the supply curve for conservation. It also outlines a methodology of estimating MC (in constant prices) by regressing total cost of conservation on total energy conserved. Empirical estimation of the MC in the residential sector is attempted in Section 3 by developing data for annualized cost of conservation capital stocks and the related energy savings. The regression of total residential energy conservation costs on total conservation provided the MC at $0.84 per million Btu (MM Btu) to the year 2000. Section 4 used time-series data for the commercial sector and obtained the MC at $0.17/MM Btu for 1980–2000. The MC of conservation in the industrial sector is estimated in Section 5 at $0.78/MM Btu for 1985–2000. In section 6, we estimate the MC in the transportation sector at $2.42/MM Btu for 1980–2000. The last section summarizes the approach and conclusions and recommends that the cost-effectiveness approach dictates that the order of priority for inducing or mandating conservation should be from the commercial to the industrial, to the residential and followed by the transportation sector for the next 20 years.

Energy Balances in the Electrorefining and Electrowinning of Copper

Using basic heat transfer correlations, the distribution of heat losses in a copper electrorefining tank house has been determined. The initial study led to programs to cover refining cells at both Kennecott refineries, with potential energy savings of approximately 1 MM Btu/ ton cathode. Only partial implementation of cell covers has been possible to date at the Utah refinery due to water availability problems which developed. The same heat balance approach can be used for copper electrowinning, although results differ significantly. In the design of a leach/solvent extraction/electrowinning facility, careful consideration must be given to the heat balance to minimize cost while maximizing cathode quality.

The economics of hydrogen and carbon monoxide separation with cuprous ammonium lactate solutions

A process is proposed for making hydrogen from coal which completely eliminates low temperature and reduces the amount of high temperature shift conversion. The resulting 1:1 H 2CO mixture is separated by absorption and reaction in a cuprous ammonium lactate solution at 1000 p.s.i.a. The hydrogen is used for large scale coal liquefaction. Regeneration of the cuprous ammonium lactate solution results in a sulfur and particulate free carbon monoxide stream suitable for electric power generation. A comparison of the economics of this alternative with conventional high and low temperature shift conversion shows an increase in the process efficiency as well as reduction in the amount of capital required. This, plus other savings, results in carbon monoxide costing 0.988 $/MSCF or 3.095 $/MM Btu. On an equivalent Btu basis, this is 70.9% of the cost of hydrogen by conventional coal conversion. Thus, substitution of separation for shift conversion results in a substantial product cost reduction.

Dual purpose power/water plants utilizing both distillation and reverse osmosis

The energy consumption of several alternate dual purpose plants are compared for application in the range of 10–50MW with 1 to 20 MGD water production. This shows that the combined gas turbine-steam turbine system is considerably more energy efficient than a steam only system. Single stage R.O., used in conjunction with this combined cycle offers the minimum overall energy consumption but has the disadvantage of producing product water with high TDS. By utilizing both R.O. and distillation, energy consumption lower than with distillation alone is achieved and product water purity is acceptable. p]A specific design of a combined dual purpose plant is presented. This plant would have a net electrical output of 29,050 kw and 3.25 MGD of 440 ppm TDS, requiring 297.1 BTU/hr. The total capital costs of this combined plant is estimated at $41,150,000 and annual operating costs at $15,087,000. The unit production costs with fuel at $2.50/MM BTU would be 4.08¢/kw-hr and $2.44 per 1000 gal. This represents an annual savings of $1,961,000 over single purpose production or 44.5% reduction in water production costs with the same electrical production costs. p]It is concluded that the combined dual purpose plant presented is the most efficient, economical and flexible method of producing power and water in the range of 10 to 50 MW and 1 to 20 MGD.

Equipment Performance in an Alberta High-Pressure Steam Injection

Abstract An experimental steam injection project conducted by Northwestern Refining Co. and McWood Corporation during 1966 at Hughenden, Alberta has shown that it is feasible to inject high-pressure steam (1,500–1,600 psig) at high rates (22 MM Btu per hour) into a sandstone reservoir containing an 18°-A.P.I.-gravity crude oil at a depth in excess of 2,500 feet without experiencing serious mechanical problems and without excessive heat losses. Conventional gas-fired treaters have proved adequate in handling any emulsion problems encountered to date.