Petroleum Radiation Processing

xi

Introduction

Radiation methods for petroleum processing have attracted the attention of research-

ers since the early 1960s when the discovery of the phenomenon of radiation-thermal

cracking presented an opportunity of using ionizing irradiation for high-rate oil pro-

cessing accompanied by profound changes in oil fractional contents and chemical

composition.

New technologies for high-viscous and heavy oil processing were developed with

technical advances in the 1990s. These technologies are now ready to be scaled up

for industrial applications. Radiation-thermal cracking of oil feedstock represents a

solution to overcoming many acute problems of the oil industry. However, processes

based on radiation-thermal cracking require heightened temperatures although they

are usually about 40% lower than those characteristic for thermocatalytic cracking.

This is acceptable for many renery operations; however, other applications, such as

oil upgrading near the sites of its extraction, require radical reduction of the process

temperature.

Observation of radiation-induced chain cracking reactions in hydrocarbons at low-

ered temperatures initiated the development of improved technological approaches,

combining the advantages of radiation-thermal cracking and low-temperature feed-

stock processing.

Progress in radiation technologies for oil processing is associated with more

detailed elaboration of the theory of thermally and radiation-induced self-sustaining

cracking reactions. Researchers still face serious difculties in the practical appli-

cation of the theory to experimental data interpretation. A kinetic description of

chain cracking reactions available in the literature is often in contradiction to the

thermodynamic requirements of endothermic chain reactions. It presents difcul-

ties in determining the correct starting cracking temperature and in predicting its

dependence on the dose rate in the case of radiation-thermal cracking. Methods for

determining the number of chain propagation steps and their dependence on experi-

mental conditions are not sufciently developed. The reactions and the nature of the

molecular states responsible for chain propagation in the case of low-temperature

radiation cracking require further research.

The objective of this book is to ll this theoretical gap. The book provides sys-

tematic descriptions of the fundamentals of radiation-induced cracking reactions in

hydrocarbons and analyzes the basic experiments that have given rise to the rapid

development of radiation technology for petroleum radiation processing during the

last decades. It also provides a detailed introduction to radiation methods based on

radiation-thermal and low-temperature cracking of hydrocarbons, with an emphasis

on high-viscous oil feedstock that are difcult to process by conventional methods,

such as heavy and high-parafnic crude oil, fuel oil, and bitumen. The application

of promising radiation methods for solving such pressing environmental issues as oil

desulfurization and regeneration of used lubricants and other used oil products also

receives special attention.

xii Introduction

The research in the last 50 years since the discovery of the phenomenon of radi-

ation-thermal cracking of hydrocarbons has resulted in impressive fundamental

ndings and promising technological approaches to the most acute issues in the oil

industry. The principal achievements in this eld of radiation science are summa-

rized in this book.

This book will be of interest to chemical technologists and researchers working

on technological applications of methods that use ionizing irradiation for oil upgrad-

ing, rening, and desulfurization. It can also be useful for students specializing in

the elds of chemical and petroleum engineering, physical chemistry, radiation phys-

ics, and chemistry.