Novel CO₂-negative design of palm oil-based polygeneration systems

A palm oil-based polygeneration system (POPS), which is a combination of a fixed bed hydrotreating reactor (FBHTR), a three-phase separator, and a series of cryogenic separators, is co-production process of green diesel and liquefied petroleum gas (LPG) named Design 1. The FBHTR model is validated by experiment data and its optimal operating parameters are determined by solving the response surface methodology-based optimization algorithm. Two CO₂-negative designs for the POPS named Designs 2 and 3 adopt approaches of (i) the evacuated tube solar collector (ETSC) for reducing 35% flue gas from the furnace, (ii) the amine-based CO₂ capture process coupling with pre- or post-separation system for producing the high-purity CO₂ product, and (iii) the heat integration design for reducing the energy duties of hot/cold utilities. Design 2 is validated to achieve the maximum negative net CO₂ emissions. Design 3 not only ensures the negative net CO₂ emissions, but also it produces three high-purity products (98.3% green diesel, 100% LPG, and 99.9% CO₂) simultaneously.