Perspectives on Sustainability in Natural-Gas-Liquids Operations Through a Cleaner Production Framework

Abstract

Sustainability in design and operation of industrial processes has become a global issue in process engineering. Of late, there has been keen interest in operationalizing sustainability particularly in the oil and gas processing industries. One way of operationalizing sustainability is to combine ‘process integration’ and ‘process optimization’ in a framework that allows engineers to significantly improve operating efficiencies. In this study, methods, mechanisms and perspectives for integrating waste minimization and process parameter optimization in order to improve operating efficiencies in natural-gas-liquids (NGL) process systems are discussed. The aim of the analysis is to provide a basis for; reducing wastes, increasing the efficiency of materials processing, as well as optimize the consumption of natural gas in NGL operations and processing facilities. The solution trajectory for operationalizing sustainability was developed by creating an innovative cleaner-production-based framework that addresses sustainability concepts through process system optimization and implementation of optimal production operation strategies. To this end, opportunities for cleaner production assessments in NGL operations and processing systems were investigated. Cleaner production alternatives were examined and evaluated with respect to in-place environmental management systems. An adapted cleaner production model that dynamically incorporates; (a) process integration, (b) process optimization, (c) optimal production operation strategies, and (d) operational excellence in a bid to deploy sustainability concepts in NGL plants was developed. The applicability of the proposed model was illustrated through a case study of an existing NGL plant in Qatar. It was concluded that innovative cleaner production models that take cognizance of existing environmental management systems can quickly reveal sustainability initiatives in NGL process systems.

Nomenclature

Hg:

Mercury

CO₂ :

Carbon dioxide

H₂S:

Hydrogen sulphide

RSH:

Mercaptan compounds

COS:

Carbonyl sulphide

CO:

Carbon monoxide

CH₄ :

Methane

VOC:

Volatile organic compounds

SO₂ :

Sulphur dioxide

Cl₂ :

Residual chlorine

SO_x :

Sulphur oxides

NO_x :

Nitrogen oxides

NGL:

Natural gas liquids

BATs:

Best available technologies

EMS:

Environmental management systems

CP:

Cleaner production

AGRU:

Acid gas removal unit

SRU:

Sulphur recovery unit

GDU:

Glycol dehydration unit