The 4th volume of "Engineering Chemistry" contains articles presenting research results related to oil processing technologies, modelling and simulation of hydrogen production processes using membrane reactors, and features of the transesterification technology of the waste cooking oil in biodiesel production. Some articles are devoted to the latest biotechnologies for biomass processing and chemical analysis of bioactive compounds and antimicrobial components of propolis from various geographic zones. This volume will be useful to specialists from the petroleum industry, applied biotechnologies and hydrogen production.