Formic Acid as a Hydrogen Donor for Catalytic Transformations of Tar

Vladimir V Chesnokov,Pavel P Dik,Aleksandra S Chichkan

doi:10.3390/en13174515

Abstract

Specific features of the catalytic tar cracking in the presence of formic acid, BEA zeolite and 8% Ni-2.5% Mo/Sibunit catalyst were studied at 350 °C and 1.0 MPa pressure. The obtained results evidenced that formic acid can be used as a hydrogen donor during catalytic reactions. The formic acid addition made it possible to perform efficient hydrocracking of heavy feed such as tar. It was found that both the tar conversion and selectivity to light (gasoline-diesel) fractions grew in the sequence: tar < (tar - formic acid) < (tar - formic acid - BEA zeolite) < (tar - formic acid - BEA zeolite - 8% Ni-2.5% Mo/Sibunit catalyst). Furthermore, significantly lower concentrations of impurities containing sulfur and nitrogen were observed for the (tar - formic acid - BEA zeolite - 8% Ni-2.5% Mo/Sibunit catalyst) system. For example, the sulfur and nitrogen concentrations in the tar precursor were 1.50% and 0.86%, respectively. Meanwhile, their concentrations in the liquid products after the catalytic cracking were 0.73% and 0.18%, respectively.

Highlights

Due to increasing worldwide demand for motor fuel, the need to utilize non-traditional heavy oil feedstock (HOF), including heavy oils, natural bitumen, heavy residual oil fractions, bituminous sands and pyroshales is rapidly growing
There is great interest in hydrocracking of heavy residual oil fractions, tar, aimed at the production of the main products of the gasoline and diesel fractions that are in great demand
At 350 ◦ C the tar carbonization resulted in the formation of gaseous and liquid products as well as oil coke

Summary

Introduction

Due to increasing worldwide demand for motor fuel, the need to utilize non-traditional heavy oil feedstock (HOF), including heavy oils, natural bitumen, heavy residual oil fractions (tar, black oil), bituminous sands and pyroshales is rapidly growing. A number of methods for deep processing of heavy oil fractions, heavy oils and oil residues in the presence of catalysts have been reported. Traditional approaches to HOF processing can be divided into two main types [1,2,3,4]. The first type includes deasphalting, thermal processes: gasification and carbonization (delayed, flexicoking, etc.), viscosity breaking and catalytic cracking. The second type includes various hydrogenation processes. There is great interest in hydrocracking of heavy residual oil fractions, tar, aimed at the production of the main products of the gasoline and diesel fractions that are in great demand. The chemistry of hydrogenation processes is based on the efficient use of hydrogen

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Results

Conclusion