Multiperiod Design and Optimization of Coprocessing of Vacuum Gas Oil and Bio-oil Integrating Supply Fluctuations of Lignocellulosic and Algal Biomass

Abstract

The coprocessing of bio-oil and vacuum gas oil has been demonstrated as a cost-effective way to utilize bioenergy. A multiperiod model is built to design and optimize of the coprocessing system by integrating monthly changes of lignocellulosic biomass production and algae growth rate. The case study showed that the optimal configurations of a coprocessing system with a minimized total annual cost can be attained with the proposed multiperiod model. The feed compositions of lignocellulosic and algal biomass for fast pyrolysis in each period were obtained by integrating the synergistic effect of copyrolysis of the two biomasses. Due to the relatively large capital investments of fast pyrolysis and algal growth process, the operational factors of the two processes were near 100% in all of the periods. A sensitivity analysis was also carried out to discuss the parameter effects. The proposed model not only can be used in the optimization of the coprocessing system but also can be adopted in bioenergy utilization.

Multiperiod Two-Stage Stochastic Programming of Supply Chain for Co-Processing System of Bio-Oil and Heavy Oil

“…Based on Wu et al’s study, mass balances of the co-processing system mainly contain the straw supply, straw storage, algae cultivation process, fast pyrolysis, bio-oil HDT, crude oil distillation unit, FCC, and HDTs for cracked diesel and cracked gasoline. Equations to calculate the mass balance of each process are listed in Table . s u i s , GF ( ω ) = g r i ( ω ) R sg z i GtD d m i s , D ( ω ) = s u i s , GF ( ω ) s u i s , D ( ω ) = z i GtD d m i s , D ( ω ) z i AtF d...…”

“…The TAC mainly contains four parts: crude oil, depot, fast pyrolysis, and algae growth. The crude oil cost is the largest proportion in TAC as crude oil consumption is much larger than other raw materials . In the cost of the depot, the straw cost is the major cost compared to the lower capital investment of the depot.…”

“…Based on Wu et al’s study, mass balances of the co-processing system mainly contain the straw supply, straw storage, algae cultivation process, fast pyrolysis, bio-oil HDT, crude oil distillation unit, FCC, and HDTs for cracked diesel and cracked gasoline. Equations to calculate the mass balance of each process are listed in Table . where su is the supply, in t·m –1 ; gr is the grain production, in t·m –1 ; R sg is the straw grain ratio; dm is the demand, in t·m –1 ; z is the binary variable, 0 or 1; y is the product yield, in %; R i s,FP (ω) is the straw feed ratio of fast pyrolysis in each period, in %; R HDO,FCC and R VGO,FCC are HDO oil co-processing ratio and VGO co-processing ratio, in %; Cap FCC is the capacity of FCC, in t·y –1 ; subscript i represents period set, in month; superscripts s, GF, sg, GtD, D, AtF, a, AG, bms, FP, bo, bg, bc, DtF, boHDT, VGO, FCC, CO, CDU, HDO, CD, CDHDT, CG, and CGHDT denote straw, grain farmland, straw grain ratio, grain farmland to depot, depot, algae, algae growth process, biomass, fast pyrolysis, bio-oil, biogas, biochar, depot to fast pyrolysis, bio-oil hydrotreating process, vacuum gas oil, fluid catalytic cracker, crude oil, crude oil distillation unit, HDO oil, cracked diesel, cracked diesel hydrotreating process, cracked gasoline and cracked gasoline hydrotreating process, respectively.…”

“…The 10 discretized levels can ensure that the whole range of distribution is covered for each IRV. The details of each IRV discretizing are listed in Table . ,, …”

“…Zhang et al proposed a mixed integer linear programming (MILP) for the co-processing supply chain and obtained optimal configurations of collections, storages, and transportation for biomass and crude oil. Wu et al built a multiperiod optimization model for the co-processing supply chain considering monthly supply changes of straw and algae. The optimal biomass supply including straw and algae as well as the monthly material balance of the co-processing process was obtained.…”